1. Field of the Invention
This invention relates to a hybrid integrated circuit device to be used as, for example, a controller for an AC generator for a car.
2. Description of the Prior Art
FIG. 1 is a circuit diagram showing an AC generator for a car and its controller. In FIG. 1, reference numeral 1 designates an AC generator having, for example, armature coils 101 connected with one another in the three-phase star connection and a field coil 102. Reference numeral 2 designates a rectifier, for example a full wave rectifier having a rectified output terminal 201, a grounded terminal 202 and input terminals 203 connected to the outer ends of the armature coils 101, and further having diodes connected between the input terminals 203 and the rectified output terminal 201 or between the input terminals 203 and the grounded terminal 202 respectively.
Reference numeral 3 designates a voltage regulator having voltage dividing resistors 301 and 302 for detecting the voltage of the generator 1, which resistors 301 and 302 are connected in series mutually between the rectified output terminal 201 of the rectifier 2 and ground, a capacitor 308 connected between the node 301a of these voltage dividing resistors 301, 302 and ground, a Zener diode 303 the cathode of which is connected to the node 301a, a control transistor 304 the base of which is connected to the anode of the Zener diode 303 and the emitter of which is grounded, a base current supplying resistor 305 one end of which is connected to the collector of the control transistor 304, a switching device, for example, a power transistor 306 the base of which is connected to the collector of the control transistor 304 and the emitter of which is Grounded and further the collector of which is connected to the rectified output terminal 201 of the rectifier 2 through the field coil 102 of the AC Generator 1, and suppression diode 307 the anode and the cathode of which are connected to the collector of the power transistor 306 and to the rectified output terminal 201 respectively.
Reference numeral 4 designates storage batteries connected between the rectified output terminal 201 of the rectifier 2 and ground, reference numeral 5 designates a key switch connected between the positive terminal of the storage batteries 4 and the base current supplying resistor 305 in the voltage regulator 3, and reference numerals 6 and 7 respectively designate a starter switch and a starter connected in series with each other and in parallel to the storage batteries 4. The rectifier 2, the voltage regulator 3, the storage batteries 4, the key switch 5, the starter switch 6 and the starter 7 compose the controller.
Next, the operation thereof will be described. In this controller, when the key switch 5 is turned on, the voltage of the storage batteries 4 is not so high as to make the Zener diode 303 conductive at this point of time, and consequently, the control transistor 304 is non-conductive. Then, a current flows from the storage batteries 4 to the base of the power transistor 306 through the base current supplying resistor 305, and consequently the power transistor 306 turns on to become conductive. As a result, a field current flows from the storage batteries 4 to the field coil 102. And, when the starter switch 6 is turned on, the starter 7 is actuated by the storage batteries 4 to be rotated, then the engine (not shown) connected to the starter 7 starts to move. The AC generator 1 is driven by the start of the moving of the engine to begin to generate electrical energy, and the output voltage of the AC generator 1 is raised.
However, when the output voltage of the AC generator 1 is lower than a predetermined value, the Zener diode 303 and the control transistor 304 is not conductive, and the power transistor 306 remains in its conductive state. Thereby, the field current flowing in the field coil 102 increases, and the output voltage of the AC generator 1 is further raised. When the output voltage of the AC generator 1 exceeds the predetermined value, the Zener diode 303 and the control transistor 304 become conductive, and the power transistor 306 becomes non-conductive. As a result, the field current decreases, and the output voltage also falls. By repeating the operation mentioned above, the output voltage of the AC generator 1 is regulated to a predetermined value by the voltage regulator 3. The capacitor 308 performs the function of smoothing the voltage detected by the dividing resistors 301 and 302.
The capacitor 308, the power transistor 306, the dividing resistors 301, 302, the Zener diode 303, the control transistor 304, the base current supplying resistor 305, the suppression diode 307 and the like of the controller are mounted on a printed board to compose a hybrid integrated circuit device.
A conventional hybrid integrated circuit device of this kind will be described with reference to FIG. 2 and FIG. 3. FIG. 2 is a perspective view of its appearance, and FIG. 3 is a longitudinal sectional view of the device shown in FIG. 2.
In FIG. 2 and FIG. 3, reference numeral 8 designates an integrated circuit board. External terminals 801 are disposed at suitable positions on it, and function elements 802, 803 and 804 are mounted on it. The function element 802 corresponds to the power transistor 306 shown in the circuit diagram of FIG. 1, and the function element 803 similarly corresponds to the dividing resistors 301, 302, the Zener diode 303, the control transistor 304, the base current supplying resistor 305, and the suppression diode 307 shown in the circuit diagram of FIG. 1, and further the function element 804 corresponds to the capacitor 308 shown in the circuit diagram of FIG. 1. Reference numeral 9 designates a ring enclosing the function elements 802, 803 and 804 on the integrated circuit board 8, and reference numeral 10 designates a protection resin (for example, silicon in a gel state) which is filled in the ring 9 so as to cover the function elements 802, 803 and 804. The protection resin 10 is injected into the ring 9 from the opening 9a of the ring.
The hybrid integrated circuit device constructed as mentioned above protects the function elements 802, 803 and 804 from the stress caused by vibrations or heat, and from moisture and so on.
Because the top part of the ring 9 of the conventional hybrid integrated circuit device is open as shown in FIGS. 2 and 3, the device has the danger of damaging the function elements 802, 803 and 804, or the danger of breaking its reed parts when a force holding down the device is imposed on the opening 9a of the ring 9 in case of handling or carrying the device in the opened state. And the device has a problem that the effect of protecting the function elements 802, 803 and 804 from the stress caused by vibrations, heat or the like, and from moisture etc. is too small in the case where the protection resin 10 exposed to the outside at the opening 9a is damaged by being scraped and so on.